172 research outputs found

    Amide proton transfer weighted imaging in pediatric neuro-oncology:initial experience

    Get PDF
    Amide proton transfer weighted (APTw) imaging enables in vivo assessment of tissue-bound mobile proteins and peptides through the detection of chemical exchange saturation transfer. Promising applications of APTw imaging have been shown in adult brain tumors. As pediatric brain tumors differ from their adult counterparts, we investigate the radiological appearance of pediatric brain tumors on APTw imaging. APTw imaging was conducted at 3 T. APTw maps were calculated using magnetization transfer ratio asymmetry at 3.5 ppm. First, the repeatability of APTw imaging was assessed in a phantom and in five healthy volunteers by calculating the within-subject coefficient of variation (wCV). APTw images of pediatric brain tumor patients were analyzed retrospectively. APTw levels were compared between solid tumor tissue and normal-appearing white matter (NAWM) and between pediatric high-grade glioma (pHGG) and pediatric low-grade glioma (pLGG) using t-tests. APTw maps were repeatable in supratentorial and infratentorial brain regions (wCV ranged from 11% to 39%), except those from the pontine region (wCV between 39% and 50%). APTw images of 23 children with brain tumor were analyzed (mean age 12 years ± 5, 12 male). Significantly higher APTw values are present in tumor compared with NAWM for both pHGG and pLGG (p &lt; 0.05). APTw values were higher in pLGG subtype pilocytic astrocytoma compared with other pLGG subtypes (p &lt; 0.05). Non-invasive characterization of pediatric brain tumor biology with APTw imaging could aid the radiologist in clinical decision-making.</p

    Interventions for treating asymptomatic impacted wisdom teeth in adolescents and adults

    Get PDF
    The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.TG Mettes, MEL Nienhuijs, WJM van der Sanden, EH Verdonschot, AJM Plasschaer

    Ciliated Epithelial Cell Differentiation at Air-Liquid Interface Using Commercially Available Culture Media

    Get PDF
    The human nasal epithelium contains basal stem/progenitor cells that produce differentiated multiciliated and mucosecretory progeny. Basal epithelial cells can be expanded in cell culture and instructed to differentiate at an air-liquid interface using transwell membranes and differentiation media. For basal cell expansion, we have used 3T3-J2 co-culture in epithelial culture medium containing EGF, insulin, and a RHO-associated protein kinase (ROCK) inhibitor, Y-27632 (3T3 + Y). Here we describe our protocols for ciliated differentiation of these cultures at air-liquid interface and compare four commercially available differentiation media, across nine donor cell cultures (six healthy, two patients with chronic obstructive pulmonary disease (COPD), and one with primary ciliary dyskinesia (PCD)). Bright-field and immunofluorescence imaging suggested broad similarity between differentiation protocols. Subtle differences were seen in transepithelial electrical resistance (TEER), ciliary beat frequency, mucus production, and the extent to which basal cells are retained in differentiated cultures. Overall, the specific differentiation medium used in our air-liquid interface culture protocol was not a major determinant of ciliation, and our data suggest that the differentiation potential of basal cells at the outset is a more critical factor in air-liquid interface culture outcome. Detailed information on the constituents of the differentiation media was only available from one of the four manufacturers, a factor that may have profound implications in the interpretation of some research studies

    Examination of the genetic factors underlying the cognitive variability associated with neurofibromatosis type 1

    Get PDF
    Purpose: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder associated with cognitive deficits. The NF1 cognitive phenotype is generally considered to be highly variable, possibly due to the observed T2-weighted hyperintensities, loss of heterozygosity, NF1-specific genetic modifiers, or allelic imbalance. Methods: We investigated cognitive variability and assessed the contribution of genetic factors by performing a retrospective cohort study and a monozygotic twin case series. We included data of 497 children with genetically confirmed NF1 and an IQ assessment, including 12 monozygotic twin and 17 sibling sets. Results: Individuals carrying an NF1 chromosomal microdeletion showed significant lower full-scale IQ (FSIQ) scores than individuals carrying intragenic pathogenic NF1 variants. For the intragenic subgroup, the variability in cognitive ability and the correlation of IQ between monozygotic NF1 twin pairs or between NF1 siblings is similar to the general population. Conclusions: The variance and heritability of IQ in individuals with NF1 are similar to that of the general population, and hence mostly driven by genetic background differences. The only factor that significantly attenuates IQ in NF1 individuals is the NF1 chromosomal microdeletion genotype. Implications for clinical management are that individuals with intragenic NF1 variants that score <1.5–2 SD below the mean of the NF1 population should be screened for additional causes of cognitive disability

    A cluster randomised controlled trial in primary dental care based intervention to improve professional performance on routine oral examinations and the management of asymptomatic impacted third molars: study protocol

    Get PDF
    BACKGROUND: Routine oral examination (ROE) refers to periodic monitoring of the general and oral health status of patients. In most developed Western countries a decreasing prevalence of oral diseases underpins the need for a more individualised approach in assigning individualised recall intervals for regular attendees instead of systematic fixed intervals. From a quality-of-care perspective, the effectiveness of the widespread prophylactic removal of mandibular impacted asymptomatic third molars (MIM) in adolescents and adults is also questionable. Data on the effectiveness of appropriate interventions to tackle such problems, and for promoting continuing professional development in oral health care are rare. METHODS/DESIGN: This study is a cluster randomised controlled trial with groups of GDPs as the unit of randomisation. The aim is to determine the effectiveness and efficiency of small group quality improvement on professional decision-making of general dental practitioners (GDPs) in daily practice. Six peer groups ('IQual-groups') shall be randomised either to the intervention arm I or arm II. Groups of GDPs allocated to either of these arms act as each other's control group. An IQual peer group consists of eight to ten GDPs who meet in monthly structured sessions scheduled for discussion on practice-related topics. GDPs in both trial arms receive recently developed evidence-based clinical practice guidelines (CPG) on ROE or MIM. The implementation strategy consists of one interactive IQual group meeting of two to three hours. In addition, both groups of GDPs receive feedback on personal and group characteristics, and are invited to make use of web-based patient risk vignettes for further individual training on risk assessment policy. Reminders (flow charts) will be sent by mail several weeks after the meeting. The main outcome measure for the ROE intervention arm is the use and appropriateness of individualised risk assessment in assigning recall intervals, and for the MIM-intervention group the use and appropriateness of individualised mandibular impacted third molar risk management. Both groups act as each other's control. Pre-intervention data will be collected in study months one through three. Post-intervention data collection will be performed after nine months

    Parent of origin genetic effects on methylation in humans are common and influence complex trait variation

    Get PDF
    Parent-of-origin effects (POE) are observed when there are different effects from alleles inherited from the two parents on phenotypic measures. Here, Zeng et al. study POE on DNA methylation in 5,101 individuals and identify genetic variants that associate with methylation variation via POE and their potential phenotypic consequences

    Poor adherence to antibiotic prescribing guidelines in acute otitis media—obstacles, implications, and possible solutions

    Get PDF
    Many countries now have guidelines on the clinical management of acute otitis media. In almost all, the public health goal of containing acquired resistance in bacteria through reduced antibiotic prescribing is the main aim and basis for recommendations. Despite some partial short-term successes, clinical activity databases and opinion surveys suggest that such restrictive guidelines are not followed closely, so this aim is not achieved. Radical new solutions are needed to tackle irrationalities in healthcare systems which set the short-term physician–patient relationship against long-term public health. Resolving this opposition will require comprehensive policy appraisal and co-ordinated actions at many levels, not just dissemination of evidence and promotion of guidelines. The inappropriate clinical rationales that underpin non-compliance with guidelines can be questioned by evidence, but also need specific developments promoting alternative solutions, within a framework of whole-system thinking. Promising developments would be (a) physician training modules on age-appropriate analgesia and on detection plus referral of rare complications like mastoiditis, and (b) vaccination against the most common and serious bacterial pathogens
    • …
    corecore